Sand-blast apparatus.



PATBNTED APR. 24, 1906.

J. D. MURRAY.

SAND BLAST APPARATUS.

APPLIOATION FILED MAY 5, 1905.

3o zle or nozzles,

UNITED STATES PATENT OFFICE JOHN D. MURRAY, OF SAN FRANCISCO, CALIFORNIA.

SAND-BLAST APPARATUS.

Specification of Letters Patent.

Patented April 24, 1906.

Application filed May 5,1905. Serial No. 258.965.

10 alt whom it may concern:

Be itknown that I, JOHN D. MURRAY, a citizen of the United States of America, residing at San Francisco, county of San Francisco, and State of California, have invented certain new and useful Improvements in Sand-Blast Apparatus; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to certain improve ments in what is technically called the sand blast, and especially to the application of this art to scaling and cleansing marine vessels of iron or steel and other structures of like nature, also of the parts-such as plates, bars, or castings of metalthat enter into such structures, and is an improvement on previous Letters Patent No. 773,665, date November 1, 1904, and No. 783,218, dated February 21, 1905, both relating to sand-blast apparatus for like purposes.

My present im rovement consists in a series, preferably t cc, of inductive nozzles, and between these, or anterior tothe last one, a second or sup lementary inlet-wa for sand and detritus t at is'drawn in an applied successively through the scouring nozculation of chilled iron shot or iron san that has greater abrasive effect, but is too expensive to be applied once and wasted, as in the case of common sand also consists in means of closing the first inlet for pure sand, so the third or second and third nozzle and the same apparatus can be em loyed to discharge waste sand and debris om where it has accumulated, within a vessel, for example.

My invention also includes a sand containing rece tacle with the compartments forming a re ay or reserve store of sand, so the a plication can be continuous and without the delay for refilling, also an improved open-ended hollow needle-valve that receives air through its axis to impinge centrally in the induction-passage; further consists in an improved form of nozzles that adds to their effect and ermits their easy and inexpensive renewal when abraded by the sand and includes means to sustain and ad'ust the apparatus, as hereinafter describe and illustrated.

The objects of my invention are to permit the use of abrading material, including chilledthus enabling the use b ciriron sand, in such manner that it will be circulated and not wasted and by means of the same apparatus remove when required from inclose places accumulated spent sand and detritus that causes hindrance of the work, such as from the interior of ships, also to increase the force and efficiency of the sand-jet and provide for its continuous application.

To these ends I employ apparatus as shown in the accompanying drawings, forming a part of this specification.

' Figure I is a longitudinal section through the nozzles and operating parts, also indicat: ing the manner of supporting the movable arts of the same and for supplying sand r om an elevated point, as in the rigging of ships; Fig. II, a side view, partially in section, of my improved apparatus, including a two-compartment receiver in an operatmg position.

It is Well known that in inductive apparatus a series of throats 0r successive impulses add force to the fluid or substance being impelled; also, it is known that the abrasive effect of chilled iron sand is'much greater than can be attained by silicious sand in removing oxid or other forms of scale from iron or steel surfaces. For the attainment of'these ends I employa receiver, a containing vessel 1 for sand or other abrading material having two compartments 3 and 4, divided b a diaphragm 5, and passages'7 and 8 lea ing from the chambers 3 and 4 to the first induction nozzle or ejector 9, as shown in Fig. I. Air under pressure is admitted throu h the pipe 14 and by action of the nozzle pro uces a partial vacuum in the chambers 3 and 4. Sand 12 is admitted through the pipes 7 or 8 from one of the chambers 3 or 4 to the ejector 9 and is forcibly driven into the pipe '13 by air under pressure entering from the pipe 14, which is connected to an air compressor or pump in the usual manner.

Fresh sand or other abrading material is supplied through the screw-nipples 11, and its flow to the nozzles is regulated by the valves 15 and 17, and the amount of air is controlled by the needle-valve 18, which is moved forward and backward by the handwheel 19 to regulate the size of the throat- Way of the nozzle 9, as seen in Fig. I. In this manner by alternately filling and connecting the two compartments of the receiver 1 the operation of the apparatus becomes continuous, and no time is lost while IIO refilling the receiver with sand. This needlevalve 18 is-made hollow andperforated on two or more sides to admit air to its interior, which is discharged centrally. This latter provision disposes the sand or ahrading material in an annular section, removing the core thereof, and adds to force imparted by the air. This feature I apply to all the nozzles 9, 20, and 22, the action being the same in each case.

. In Fig. I, where only two nozzles are shown, the middle one 20 being omitted, I

show a suspended vessel 23 for containing 2 the sand or other abradingmaterial, such as is required in operating in places where there is no room for a receiver, such as shown in Fig. II. This vessel 23 can be slung to a ships rigging or beneathdecks, the first nozzle 9 being also suspended, as indicated at 24, a hose 25 conveying the sand or abrading material to the first nozzle 9 and air under pressure entering the nip le 26.

Referring to Fig. II, w ich indicates the manner of operating when two movable nozzles are employed, 27 is a plate being acted u on, the supply-valves 15. and 17 being 0 osed and the sand or abrading material 12 falling down to be drawn into a suction-nozzle 28 and circulated through a hose 29, a

partial vacuum being maintained in this hose y the inductive action of the nozzle 22. This manner of operating is especially applicable in the case of using iron sand, which can be returned to either of the nozzles 22 or 20, also to the receiver 1 and first nozzle 9, by

-means of a pipe 10, to which the hose 31 can connect from the suction-intake '28, as shown in Fig. II. The apparatus when arranged in the manner shown and the valves 15 and 17 closed can be used to remove s ent sand and dust from the hold of a vesse or other con.

fined place through the nozzle 22, this latter being directed overboard or to a suitable receptacle for the debris, as will be understood. The nozzle-tip 30, which is especially sub ject to wear, I make in the form of thimble or shell to fit within a screw-follower 32, thereby providing for the instant removal 2nd iieplacement of the tip 30, as shown in The abrading material may consist of ure silicious or common sand or iron san or these'can be mixed together, which is common; so, also, can the number of nozzles" be varied, as before explained. The circumstances of use are'extremely varied and call for modifications of various kinds to attain the best results. Having thus explained the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In sand-blast apparatus, an ejectingnozzle, a receiver for the abrasive material discharged therethrough, and a pipe connecting said receiver with said nozzle at the rearof the latter, whereby said material isreturned and used continuously by the action of the air-blast, substantially as specified.

2. In sand-blast apparatus, a series of ejectin -nozzles acting cumulatively, a reservoir or abrasive material communicating with the rear nozzle of the series, means for supplying an air-blast a receiver for the abrasive material discharged from said nozzles, and a pipe connecting said receiver with the foremost nozzle at the rear thereof, for circulating said abrasive material, substantially as specified.

3. In sand-blast apparatus, a reservoir for containing abrasive material, means for supplying an air-blast, a series of ejecting-nozzles connected by a pipe with said reservoir, an ejector between said air-supply and said pipe connection, and a hollow adjustable needle-valve, perforated in its sides, in said ejector, for regulating the air-blast and causing a graduated central discharge through the ejector, substantially as specified.

4. In sand-blast apparatus, a series of ejectingmozzles, a suspensory reservoir for abrasive material, pipe connections between said nozzles and said reservoir, an ejector. in said suspensory reservoir, means for supplying sand and air under pressure to said reser- 'voir, and a hollow adjustable needle-valve to 

